A variety of pump control systems are known in the prior art. Many of these systems can be used to control fluid levels in tanks or sumps.
Representative prior art systems include those disclosed in U.S. Pat. No. 6,565,325 entitled “Sensor Based Control System”, and in U.S. Pat. No. 5,707,211 entitled “Variable Speed Pump System with a Hydropneumatic Buffer/Pressure Tank”. Each of the noted patents is assigned to the Assignee hereof and is incorporated herein by reference.
In various of the known pump control systems levels are sensed by switch carrying floats. Others use electromechanical components for switching electrical energy to the respective pump motor or motors.
It has been recognized that it would be desirable to eliminate electromechanical or mechanical components from such systems to improve reliability thereof. There is thus an ongoing need for more reliable pump control systems. Preferably such improved reliability can be achieved without substantially increasing either the manufacturing costs or the complexity of such systems.